1. Field of the Invention
The instant invention relates to that field of methods for producing articles of manufacture known as candles. Specifically, the instant invention is a method for producing candles having three dimensional designs upon their exterior surfaces.
2. Background Information
The prior art known to applicant discloses that the art of candle making is well known. Historically, candles are one of the oldest known means for supplying light. References to candles date to at least 3000 B.C. in Crete and Egypt. It is believed that molds were first used in candle making in Paris during the 15th century. During the 19th century, candle making enjoyed a renaissance. A number of "modern" technical innovations were introduced which eliminated many of the unpleasant aspects of candle burning. Furthermore, the industrial revolution left its mark on the candle making industry at this time with the advent of mechanical candle making machines.
The prior art discloses that there are a limited number of methods known for making candle molds. Five basic types of flexible mold compounds are most often used. Included in these mold compounds are so called "Hot-Melt" (polyvinyl chloride) systems, latex systems, silicone rubber systems, polysulfide rubber systems and polyurethane flexible mold compounds.
The prior art further discloses that there are five basic types of molds which may be created using the above compounds. These are the flat-back one piece mold, the split one-piece mold (unshelled), the one-piece mold (shelled), the split one-piece mold (shelled) and the multi-piece mold (shelled or unshelled).
Producing a candle having any sort of surface design has been a difficult process. By the term "surface design", Applicant means any sort of ornament or design which may be created on the exterior surface of the candle. Examples of surface designs include lettering, graphic designs, and simple textures such as striations, crosshatching and the like.
Until inventor's method, surface designs such as lettering and graphic designs were difficult to produce. For example, if one wished to apply a series of letters to the surface of the candle, one would have two basic choices: impress the letters into the candle; or create a mold which would produce letters which stood out from the surface of the candle or were incised into the surface of the candle.
In the first case, impressing the letters into the candle, a number of difficulties are encountered. First, a suitable stamp must be produced. This was most often accomplished in the prior art by utilizing individual metal stamps, one for each letter. Most analogous here would be the use of commercially available type used in the past by type-setters in the printing trade. These letters (either singly or strung together in a "block" and held in a frame) protruded from a back ground upon which they were mounted such that when pressed against a candle, the letter (but not the background) would appear as an indentation in the candle. Because the letter was stamped into the surface of the candle through the application of pressure to the stamp and against the candle surface, the material chosen for making the stamp had to be harder than the wax to be stamped. This meant that most rubber compounds and some plastic compounds would be too soft, and hence unsatisfactory.
Unfortunately, creating surface designs in this manner results in a second difficulty. Candle wax is ideally a reasonably hard wax. A harder wax is desirable so that when the candle is lit, only the portion directly adjacent to the burning wick will liquefy. When too soft a wax is used, the heat generated during wick burning may be transferred throughout the soft wax, which then softens further, ultimately leading to one large puddle of liquid wax where the candle once stood instead of a small puddle surrounding the wick of an intact candle.
When a harder wax is utilized, the process of stamping letters or designs into the exterior surface of the candle becomes problematic. If the design on the metal stamp is at all intricate (for example, when applying a cursive letter "g", there will be fairly deep indentations in the centers of the upper portion of the letter and the lower portion of the letter), the wax will have a tendency to remain in the indented portions of the design when the stamp is pulled free of the candle, following stamping. The more complicated the design, that is, the more indented portions locatable on the surface of the metal stamp, the greater the likelihood that some of the candle surface will be pulled free of the candle when the stamp is removed. Such pulling free of the surface of the candle ruins the design, and requires extensive manual labor to rectify.
A third problem associated with stamping into the surface of the candle is that of surface deformation. When a candle is stamped into, the wax material which is pushed free of the upraised areas on the metal stamp must go somewhere. As the candle wax is not terribly compressible, it should be clear that the wax must flow out of the indentation produced by the metal stamp, and relocate elsewhere. In practice, this means the wax will be pushed out of the recessed (incised) area created in the candle by the metal stamp, and flow onto the surface of the candle, clear of the area occupied by the stamp. Once the stamp is removed, wax fragments must be cleared from the surface. Often, these fragments are still slightly attached to the candle's exterior surface, and pulling them free will further mar the candle finish. Once marred, the surface will require additional repair and refinishing. Obviously, if one is making many copies of a candle in this manner, the amount of labor required to stamp, clean, and refinish can quickly become exorbitant.
Furthermore, the harder the wax used in making the candle, the less likely the wax is to "flow" when stamped. This means that while a particular wax may be ideally suited for use in candles, the exterior surface of that same wax may be nearly impossible to stamp into without seriously marring that surface. Not only does such marring require additional "touch up" work, but it makes application of an intricate design, with any reasonable expectation of clear surface impression resolution, nearly unattainable.
Finally, while this method may be reasonably satisfactory when applying surface designs to a candle having a relatively flat surface, it is wholly unsatisfactory in the case where a design is desired on a candle having a spherical or cylindrical configuration. In either of these cases, the stamp which is to be applied must be concave or curved at angles which match the surface of the sphere or cylinder. This means that expensive and specialized equipment must be used in order to create the stamp, thus dramatically increasing the cost of the final product.
In the second case, creating a mold which would produce letters which stood out from the surface of the candle (or were incised into the surface of the candle), a different set of problems emerges. This method usually entails the hand fabrication of an original model.
Hand fabrication of an original model means the preparation of an exact duplicate of the final product (a candle having three dimensional surface designs) using a different material than that from which the final item will be fabricated. This may be accomplished using clay, wood, metal, plastic, plaster or any other suitable material. The original model is fabricated into the shape which the final product will take. Its surface is then engraved or carved to exhibit the design or texture desired in the final product.
The engraving or carving of the surface of the original model is a laborious process. It requires a craftsman sufficiently skilled in working with both the material from which the original model made, and the art of applying (carving, engraving, chiseling) a design to that material.
The first problem created by this method is that the material used when preparing the original model must be capable of accepting and retaining the design which will appear on the final product. For example, if one uses a rough colloidal material to create the original model, it will be very difficult to engrave fine details onto its surface. While this material may be easier to carve, it will support only the grosser elements of the design, while the finer elements may be lost.
On the other hand, if one uses a material having a much finer composition (for example, glass or plastic), the process of carving the design into its surface becomes all the more difficult and labor intensive. In such a case, few craftsmen will willingly undertake an extremely intricate design.
Once the hand carved original is complete, a mold is prepared from it. The method most analogous to the instant method is the one piece split mold. This method entails creating an enclosure or "dam" around the hand carved original. This dam is most often constructed from flat, essentially square or rectangular, wood sheets. The wood sheets are constructed into a box having four sides, an open top and an open bottom. Various fasteners are used to hold the wood sheets together.
The dam is then placed on a non-porous surface, and fastened to that surface such that it will not move, nor will liquid seep out of the box. Most often this is accomplished by placing a clay or similar material along the bottom edge of the dam, and then pressing downwardly on the dam so that the clay seals the space between the dam and the non-porous surface.
When preparing the dam, its dimensions are such that a small space (generally between 1/2 of an inch and 1 inch) is present between the surface of the hand carved model, and the interior surfaces of the dam.
Liquefied rubber (or similar material) is then poured into the dam, filling the space between the dam inner surfaces and the hand carved model's exterior surface. This rubber is allowed to solidify before removing the dam. Once fully set, the rubber may be stretched or cut free of the hand carved model.
The rubber mold which has thusly been achieved is then used to create the final product. This is accomplished by building a frame snugly around the rubber mold so that the mold has support, and then pouring hot liquid wax into the mold. Candle makers often spray a releasing agent such as silicon onto the surface of the mold which will contact the hot wax, prior to the wax being poured. The wax sets as it cools, and once sufficiently set, may be pulled free of the rubber mold. The candle thus produced is a nearly identical copy of the original hand carved model, having present upon its surface all the surface designs present upon the hand carved original. The mold is then cleaned and prepared for another "casting".